class Solution {
public:
    int lengthOfLongestSubstring(string s) {
        int i=0,j=1,k,max,n=s.size();
        vector<int> a;
        while(j<n){
            while(s[i]!=s[j]){j++;}
            k = j-i;
            a.push_back(k);
            i++;
        } 
        max = *max_element(a.begin(),a.end());
        return max;
    }
};